2027 ICD-10-CM Diagnosis Code F91.9Conduct disorder, unspecified
ICD-10-CM Codes›F01–F99›F90-F98›F91
- Billable — Valid for Submission
- Not Chronic
F91.9 is a billable ICD-10-CM diagnosis code for conduct disorder, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 886. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Disruptive, impulse-control and conduct disorders.
F91.9 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 133 for payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
F91.9 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model, but it maps to payment categories in the other CMS models shown below.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Abnormal behavior
- Behavior problem of childhood and adolescence
- Behavioral disability
- Clark Baraitser syndrome
- Conduct disorder
- Conduct disorder in remission
- Disruptive behavior
- Disruptive behavior disorder
- Intellectual disability, macrocephaly, hypotonia, behavioral abnormalities syndrome
- Micrognathia, recurrent infections, behavioral abnormalities, mild intellectual disability syndrome
- Mixed behavior and emotional disorder
- Problem behavior
- Problem behavior in adult
- Ran away
- Self destructive behavior
- WAC-related facial dysmorphism, developmental delay, behavioral abnormalities syndrome
- X-linked epilepsy with learning disability and behavior disorder syndrome
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to F91.9: its own notes plus those printed at F91, block F90-F98, and Chapter 5. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- disorders of psychological development
Applicable To
Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.
- Behavioral disorder NOS
- Conduct disorder NOS
- Disruptive behavior disorder NOS
- Disruptive disorder NOS
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
Notes
General instructions on how these codes are used.
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name F91.9, its category, or a range that includes it.
Excludes1 2
These codes carry an Excludes1 note naming F91.9: they are not reported together with it, unless the two conditions are unrelated.
Excludes2 1
These codes carry an Excludes2 note naming F91.9: its condition is not part of those codes, and both may be reported when the patient has both.
Notes 1
These notes mention F91.9.
- Block F90-F98 Behavioral and emotional disorders with onset usually occurring in childhood and adolescence
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Disorder (of) See Also: Disease;
conduct (childhood) F91.9
disruptive F91.9
Disturbance (s) See Also: Disease;
conduct See Also: Disorder, conduct; F91.9
disruptive F91.9
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Conduct Disorder
a repetitive and persistent pattern of behavior in which the basic rights of others or major age-appropriate societal norms or rules are violated. these behaviors include aggressive conduct that causes or threatens physical harm to other people or animals, nonaggressive conduct that causes property loss or damage, deceitfulness or theft, and serious violations of rules. the onset is before age 18. (from dsm-iv, 1994)
Patient EducationClinical
Child Behavior Disorders
All kids misbehave some times. And some may have temporary behavior problems due to stress. For example, the birth of a sibling, a divorce, or a death in the family may cause a child to act out. Behavior disorders are more serious. They involve a pattern of hostile, aggressive, or disruptive behaviors for more than 6 months.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert F91.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About F91.9Overview
What is the ICD-10 code for conduct disorder, unspecified?
The ICD-10-CM code for conduct disorder, unspecified is F91.9 (sometimes written as F919). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is F91.9 (Conduct disorders) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report conduct disorder, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does F91.9 group to?
When conduct disorder, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 886 (behavioral and Developmental Disorders), which carries a relative weight of 1.6455. Higher weights mean higher Medicare reimbursement.
Can F91.9 be reported with a code from Z72.81?
Not as a rule. The Excludes1 note at F91, which applies to F91.9, lists "antisocial behavior (Z72.81-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What is the ICD-9 equivalent of F91.9?
Under the General Equivalence Mappings, conduct disorder, unspecified converts to ICD-9-CM 312.9 (conduct disturbance NOS). The mapping is a direct match.
Does F91.9 risk-adjust for Medicare Advantage payment?
Not for Medicare Advantage: F91.9 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 133 (Anxiety and Other Psychiatric Disorders).
